![]() | The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject.(March 2025) |
In the United States, a boxed warning (sometimes "black box warning", colloquially) is a type of warning that appears near the beginning of the package insert for certain prescription drugs, so called because the U.S. Food and Drug Administration specifies that it is formatted with a "box" or border around the text [1] to emphasize its importance. [2] The FDA can require a pharmaceutical company to place a boxed warning. It is the strongest warning that the FDA requires, and signifies that medical studies indicate that the drug carries a significant risk of preventable, serious or even life-threatening adverse effects. [2] [3]
Economists and physicians have thoroughly studied the effects of FDA boxed warnings on prescription patterns. It is not necessarily true that a physician and patient will have a conversation about a drug's boxed warning after it is issued. [4] For instance, an FDA-mandated boxed warning decreased rosiglitazone use by 70%, but that still meant 3.8 million people were given the drug. Later research indicated that after receiving an FDA advisory, there was a decrease in rosiglitazone use, due to a combined effect of media exposure, advisory, and scientific publications, whereas pioglitazone (with a similar advisory but less media exposure) did not similarly decrease in use. [5]
Boxed warnings on drugs have received increased media attention in the United States since 2004. Among some of the more widely covered stories:
In China, a warning text (警示语) may be added to a package insert, either voluntarily by the manufacturer or at the request of NMPA (formerly CFDA, the Chinese counterpart of FDA). Although no formatting requirement is found in law, the typical formatting is similar to the American counterpart with boxed text at the top of the insert. The CFDA/NMPA has used its power to mandate a warning on fluoroquinolones, ceftriaxone, aciclovir, and pioglitazone. [24]
Health Canada terms its version of boxed warnings "serious warnings and precautions box". [25] The formatting is similar to the US counterpart; an example for Paxlovid can be seen on Pfizer's website. [26]
On October 2004, the FDA required a so-called boxed warning for antidepressant drugs of any class. That warning became effective in January 2005. In 2006, the FDA warning extended to young adults aged up to 25 years, an announcement that followed a slew of media reports about the link between antidepressant drug use and suicide, possibly culminating in an exaggerated alarmist message.
The committee members were asked if they felt that based on the data for the pediatric population, there was a need for a boxed warning regarding cardiovascular risks. None on the committee expressed a need for this.
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: CS1 maint: DOI inactive as of July 2025 (link)